Melted ground wires near battery.

[DrunkBotany]

Hello all,
I have a 1985 Honda spree that I bought a couple months ago. Seemed to work alright at first, but then it started to bog down, lights were dimming, and began to have trouble starting and saw that the battery looked pretty old so replaced it. It worked great after that but I checked the voltage on a whim and saw it was not charging so started to poke around. I found a bunch of the ground wires melted coming off the battery.

So my questions are before I replace the wires:
1. What generally causes melted grounds besides a bad ground or damaged wire? (I did check out the fuses and rectifier and they seemed alright).
2. How many grounding points are there typically? I only see the one that attaches to the bolt that holds the rectifier.
3. Does anyone make wiring harnesses or have a good guide for making them or do people buy used ones? (Just in case I mess this up).

4. Any other advice at all?

Thanks for any advice, I’m pretty new to this and trying to understand the wiring diagrams/manual but it’s pretty new to me. Also added some pictures for a reference point.

[Rideslikenacho]

Just an observation but looks like the rectifier is heating up and melting them based on location of the wires.

[motormike]

Most likely positive has gone to ground somewhere
and melted the plastic from the inside by the copper getting HOT;...
not likely the rectifier is generating heat enough to melt the insulation in the fashion pictured. imho

[DrunkBotany]

Thanks for the responses, just rewired and checked ground, going to start it up this weekend and see if it charges the battery and make sure no wires start melting/rectifier doesn’t heat up. Thanks again.

[Txaero121]

any updates on this?